How+To+Create+A+Custom+AHU

**__Abstract__**- This document will provide a step by step process to create a custom sized Air Handling Unit with Parametric Duct Connections.
 * How to Create a Custom Air Handling Unit-**

1. Create a “New Family” and select “Mechanical Equipment.rft” 2. Create a “Solid” ‘Extrusion” on the Floor Plan Ref. Level with the correct dimensions and set the Height in “Extrustion Properties”. Be sure to draw each face as a continuous line, otherwise it will be difficult to select faces later. 3. To Place SA, RA, EA, and OA duct connections go to the appropriate Elevation and select the air handler. First we must click to disassociate the work plane. 4. Add a duct connector and select “Placement” by “Work Plane”. “Pick a plane” and select the air handler again. 5. If done properly the duct connection will appear and will be free to be moved to its desired location. From here we will add Parameters so the duct size can be changed later in the component dialogue box. Select the “+” for “Associate Family Parameter”. 6. “Add Parameter” and configure it to have a corresponding name. Select “Dimension” from “Group Parameter under:” and if the parameter should be free to be edited once the component is placed on a project select “Instance”. This will create a SA Height Parameter that can be later changed by each separately placed component. 7. In “Family Properties” – “Types” theses parameters can be given default values. 8. With the duct connection selected select “Element Properties” to check that the parameter was correctly added. The default value should be greyed out and have an equals sign next to it. Click the equals sign and check that the correct parameter is matching the correct dimension. The correct System type can also be properly selected here. 9. Repeat these steps until all desired connections are created. 10. Place in a new project and check to make sure your ducts are able to be extended and parameters adjusted.